Substrate carrier and facility interface and apparatus including same

ABSTRACT

A carrier comprises an enclosure, a cabinet and at least one substrate holder. The enclosure comprises a door. The cabinet is coupled to the carrier. The cabinet comprises at least one valve and contains at least one reduction fluid. The substrate holder is disposed within the enclosure to support at least one substrate.

This application claims priority of the filing date of U.S. ProvisionalPatent Application No. 60/747,445 filed May 17, 2006, which provisionalpatent application is hereby formally incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to carriers and facility interfaces, andmore particularly to semiconductor wafer carriers and facilityinterfaces.

2. Description of the Related Art

With advances in electronic products, semiconductor technology has beenapplied widely in manufacturing memories, central processing units(CPUs), liquid crystal displays (LCDs), light emitting diodes (LEDs),laser diodes and other devices or chip sets. In order to achievehigh-integration and high-speed requirements, dimensions ofsemiconductor integrated circuits have been reduced and variousmaterials, such as copper and ultra low-k dielectrics, have beenproposed along with techniques for overcoming manufacturing obstaclesassociated with these materials and requirements.

FIG. 1 is a schematic drawing showing a traditional via hole structure.A copper layer 110 is formed over a substrate 100. An ultra low-kdielectric layer 120 is formed over the copper layer 110. A via hole 130is formed within the ultra low-k dielectric layer 120 to expose the topsurface of the copper layer 110. If the copper layer 110 is exposed toair, the top surface of the copper layer 110 reacts with oxygen in air,forming a copper oxide layer 140 due to oxidation. The copper oxidelayer 140 can adversely affect the electrical connection between the topsurface of the copper layer 110 and a conductive via plug filled intothe via hole 130. In addition, the ultra low-k dielectric layer 120absorbs moisture when exposed to air. Accordingly, great care should betaken to avoid exposure to air during critical process steps, such asvia opening, formation of copper seed layers, copper chemical mechanicalpolish (CMP) and formation of the ultra low-k dielectric material.

Traditionally, after a critical process step, the substrate 100 isremoved from the process chamber that performs the critical process stepand temporarily stored in a cassette or front opening unified pod (FOUP)until subsequent processing. When the door of the cassette or FOUP isremoved to allow placement of the substrate 100 in the cassette or FOUP,air from the surrounding environment including oxygen flows into thecassette or FOUP. After the door is closed, the air is sealed within thecassette or FOUP with the substrate 100. As described above, oxygentends to react with the copper layer 110 formed over the substrate 100to form the copper oxide layer 140.

In order to address this problem, a “Q-time” is required after acritical process step is performed in the semiconductor manufacturingprocess. The next substrate process must be performed within a setpredetermined time period or Q-time, such as from 2 to 4 hours. If asubsequent process, such as formation of a barrier layer, does notoccurred within the time period, a cleaning process is required toremove any copper oxide layer 140 formed over the copper layer 110.

Due to high integration of semiconductor devices over substrate 100, asemiconductor process usually has a plurality of the critical steps eachwith an associated Q-time designed to protect the substrate. TheseQ-time requirements complicate the manufacturing processes. In addition,if a Q-time is missed, additional steps such as cleaning steps increaseprocess time and complexity.

By way of background, U.S. Pat. No. 6,506,009 provides a description ofa prior art cassette stocker, the entirety of which is herebyincorporated by reference herein. U.S. Patent Publication No.2003/0070960 provides a description of a prior art wafer cassette forstoring and transporting wafers, the entirety of which is herebyincorporated by reference herein. Neither of these references provide ameans for limiting formation of oxidation on or otherwise protectingsurfaces of substrates when substrates are stored within or transferredto cassettes or FOUPs.

From the foregoing, improved cassettes or carriers and facilityinterfaces therefor are desired.

SUMMARY OF THE INVENTION

In accordance with some exemplary embodiments, a carrier comprises anenclosure, a cabinet and at least one substrate holder. The enclosurecomprises a door. The cabinet is coupled to the carrier. The cabinetcomprises at least one valve and contains at least one reduction fluid.The substrate holder is disposed within the enclosure to support atleast one substrate.

The above and other features of the present invention will be betterunderstood from the following detailed description of the preferredembodiments of the invention that is provided in connection with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Following are brief descriptions of exemplary drawings. They are mereexemplary embodiments and the scope of the present invention should notbe limited thereto.

FIG. 1 is a schematic drawing showing a prior art via hole structure.

FIG. 2A is a schematic side cross-sectional view of an exemplary wafercarrier.

FIG. 2B is a schematic end view of the carrier of FIG. 2A shown with thedoor of the carrier removed.

FIG. 3A is a schematic illustration of an exemplary facility interface.

FIG. 3B is an enlarged drawing of the stage, carrier, sealing apparatusand wall of the enclosure shown in FIG. 3A.

FIGS. 4A-4C are schematic cross-sectional views illustrating anexemplary process of attaching the carrier 200 to the facility interface300 as shown in FIG. 3B.

FIGS. 5A-5B are schematic drawings showing exemplary pressure changeswithin an enclosure after loading and unloading of the enclosure on astage.

DESCRIPTION OF THE PREFERRED EMBODIMENT

This description of the exemplary embodiments is intended to be read inconnection with the accompanying drawings, which are to be consideredpart of the entire written description. In the description, relativeterms such as “lower,” “upper,” “horizontal,” “vertical,” “above,”“below,” “up,” “down,” “top” and “bottom” as well as derivatives thereof(e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should beconstrued to refer to the orientation as then described or as shown inthe drawing under discussion. These relative terms are for convenienceof description and do not require that the apparatus be constructed oroperated in a particular orientation.

FIG. 2A is a schematic cross-sectional view of an exemplary wafercarrier. The carrier 200 comprises an enclosure 210 comprising a door220 for opening and closing the enclosure 210. A hollow cabinet 230 iscoupled to the carrier or formed integrally therein. The cabinet 230 canbe, for example, a square, rectangular, oval or other shape that isadapted to store a fluid. FIG. 2A shows the cabinet 230 locatedproximate to a wall 260, such as the top wall, of the enclosure 210. Inother embodiments, the cabinet 230 is located away from the door 220 sothat the positioning of the cabinet 230 will not interfere transfer ofsubstrates 280. The cabinet 230 can vertically or horizontally disposedon a sidewall, top wall or bottom wall of the carrier 230. In stillother embodiments, the cabinet 230 can be disposed on the door 220. Thecabinet 230, which is essentially a tank, contains at least one fluid235 therein, shown partially filling cabinet 235. The cabinet 230includes at least one valve, such as a valve 240 and an injection valve250. At least one substrate holder 270 is disposed within the enclosure210 and coupled to at least one of the walls 260 of the enclosure 210 tocarry at least one wafer substrate, display substrate, such as liquidcrystal display (LCD), plasma display, cathode ray tube display orelectro luminescence (EL) lamp, light emitting diode (LED) substrate orreticle (collectively referred to as, substrate 280), for example.

The carrier 200 can be, for example, a cassette, front opening unifiedpod (FOUP), reticle carrier or other carrier known in the art forcarrying one or more semiconductor substrate. In an embodiment, thecarrier 200 is a FOUP and the door 220 is located on a side of thecarrier 200. In this embodiment, the carrier 200 also includes a frame225 so that the door 220 can be moved into and from the frame 225.Further, a surface 225 a of the frame 225 is attached to a sealingapparatus disposed on a facility interface (not shown in FIG. 2A, butshown in FIG. 4B). In some embodiments, the carrier 200 is a cassetteand the door 220 is located at the bottom of the carrier. In still otherembodiments, the door 220 is located at the top of the carrier 200. Thedimensions of the door 220 do not necessarily match the dimensions of aface of the enclosure 210 at which it is located as shown in FIG. 2A.For example, the enclosure 210 can comprise a sidewall 260 having anopening through which a substrate 280 can be placed. In this embodiment,the door 220 need only cover the opening. In some embodiments, the door220 is configured within or coupled to the sidewall 260 so that it canmove (e.g., slide or swing) to close and open the opening in thesidewall 260 of the enclosure 210. Alternatively, the door 220 can beremoved. From the foregoing, it should be understood that the enclosure210 need only include an opening having dimensions that allow thesubstrates 280 to be moved smoothly in and out of the enclosure 210 anda door 220 (i.e., cover) for covering the opening to seal the enclosure210.

In the embodiment of FIG. 2A, the enclosure 210 is sealed when the door220 is connected to or closed over the opening to the enclosure 210. Insome embodiments, a sealing apparatus 215 is disposed between theenclosure 210 and the door 220 to seal the carrier 200 against asurface. The sealing apparatus 215 can be disposed on the enclosure 210,door 220 or both. The sealing apparatus 215 can be, for example, arubber strip, O-ring, gel or other apparatus adapted to seal the carrier200. In other embodiments, the sealing apparatus 215 is not required ifthe enclosure 210 and the door 220 are tightly connected, such as byfasteners.

The door 220 is removed or opened to transfer at least one substrate 280into or from the enclosure 210. The enclosure 210 is connected to aninterface apparatus (not shown) during the substrate transfer. Thesealing apparatus 215 (on the enclosure 210 and/or interface apparatus)seals the gap between the enclosure 210 and the interface apparatus asdescribed in more detail below. In some embodiments, it is possible thatthe substrate 280 is exposed to the environment when the door 220 isremoved. The enclosure 210, however, is either immediately contactedwith the interface apparatus or sealed by the door 220 after thetransfer of the substrate 280. The duration of the substrate 280exposure to the environment is short enough that little reaction canoccur between the substrate 280 and the environment. In addition, inembodiments, a reduction gas is provided within the carrier 200 toreduce the oxidation as described below.

Referring to FIG. 2A, the pressure within the sealed carrier 200 ismaintained higher than the pressure of the environment surrounding thecarrier 200 in order to prevent or reduce gas flowing from environmentinto the carrier 200 during prolonged storage periods. For example, ifthe environmental pressure is about 1 atm, the pressure within thecarrier 200 is maintained higher than 1 atm. Accordingly, the requiredpressure within the carrier 200 can vary with the environmentalpressure. In some embodiments, the pressure within the carrier 200 ismaintained within a selected range, such as from about 1.0 atm to about2.5 atm. In some preferred embodiments, the pressure within the carrier200 is maintained within a selected range, such as from 1.0 atm to about1.3 atm, so that the pressure difference between the environment and thecarrier 200 will not crash the carrier 200.

The desired pressure is maintained by a gas provided in the carrier 200.The gas can comprise a reduction gas, a gas that is non-reactive withthe substrate 280 or a mixture thereof. A reduction gas can be providedto reduce or prevent oxide formation on the surfaces of the substrate280 due to exposure of the substrate 280 during transfer of thesubstrate 280 into the carrier 200 or due to air trapped in the carrier200. In some embodiments, the substrate 280 comprises exposed copperlayers (not shown in FIG. 2A, but shown in FIG. 1) and the reduction gascomprises hydrogen (H₂), ammonia (NH₃), or other reduction gas ormixture thereof. The non-reactive gas component can comprise an inertgas such as helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon(Xe), radon (Rn) or other gas such as nitrogen (N₂) that does notsubstantially react with the surfaces of the substrates 280 to form anoxide or other undesirable reaction (e.g., absorption of water within alow-k dielectric layer). In some embodiments, the non-reactive gas canbe provided into the carrier 200 by a valve coupled to the carrier 200and to an external source. In still other embodiments, the non-reactivegas may be provided into the carrier 200 from the cabinet 230 if thecabinet 230 comprises a mixture of the reduction fluid and non-reactivefluid or from a second cabinet (not shown).

The amount of the reduction gas should be controlled to preventexplosion or other volatility if the selected reduction gas is volatile.For example, if H₂ is the reduction chemical within the carrier 200, theamount of H₂ within the carrier 200 should be equal to, or less than,about 4% per volume. One preferred amount of H₂ is between about 10parts per million (ppm) to about 4% per volume with the remainingpercentage composed of at least one non-reactive gas. In someembodiments, if NH₃ is the reduction chemical within the carrier 200,the amount of NH₃ within the carrier 200 is equal to, or less than,about 15.5% per volume. One preferred amount of NH₃ is between about 10parts per million (ppm) to about 15.5% per volume with the remainingpercentage composed of at least one non-reactive gas.

In some embodiments, the sealing apparatus 215 does not completely sealthe carrier 200 and the gas within the carrier 200 is allowed to leak orflow into the environment surrounding the carrier 200, at least in smallamounts. If the gas is hazardous, such as NH₃, the gas within thecarrier 200 is controlled so that the leakage of the gas does not resultin levels harmful to human beings. For example, with NH₃ the levelsshould not be allowed to rise to 25 ppm in the environment. The amountof the gas, e.g., NH₃, within the carrier 200 may also be adjusted toeliminate this concern.

Referring to FIG. 2A, the cabinet 230 comprises at least one reductionfluid and/or non-reactive fluid 235 therein stored as a gas, liquid orboth (collectively, “fluid”). The valve 240, which comprises a needlevalve in an embodiment, releases a gas formed by the fluid 235 withinthe cabinet 230 into the carrier 200 when the pressure within thecarrier 200 is at or lower level than a predetermined or measuredpressure, for example, the environmental pressure (e.g., 1 atm). Theinjection valve 250 allows for filling the fluid 235 into the cabinet230 when the amount of the fluid 235 within the cabinet 230 is lowerthan a predetermined or desired amount. In some embodiments, the fluidcomprises a mixture of N₂ and H₂ in which H₂ is from of about 4% pervolume to of about 10% per volume. In other embodiments, the fluid 235is liquid H₂. Under the pressure within a range from about 1 atm toabout 2.5 atm and at room temperature, H₂ is in a gas phase. Once liquidH₂ is released into this environment, it converts to the gas phase andfills into the enclosure 210 of the carrier 200. In embodiments, the gasof the fluid 235 can be filled into the enclosure 210 by an installedpump (not shown). In some embodiments, a pressure gauge 261 is coupledto the valve 240 by connection 265 to send a signal to trigger the valve240 to release the reduction fluid gas. In other embodiments, thepressure gauge 261 is not required if the valve 240 is time set torelease the gas of the fluid 235 or is itself pressure sensitive.

In some embodiments, a gauge (not shown) is coupled to, or installed in,the injection valve 250. This gauge senses the amount of the fluid 235within the cabinet 230 and sends a signal to trigger the injection valve250 to fill the fluid 235 into the cabinet 230 from a source such as anexternal fluid tank (not shown) if the amount of the fluid 235 withinthe cabinet 230 is less than a predetermined amount. Alternatively, thegauge is not required if, for example, the injection valve 250 is timeset to fill the fluid 235 into the cabinet 230 or itself serves as agauge.

In some embodiments, only one of the valves 240 and 250 is used if theselected valve is configured to allow both the injection of thereduction fluid 235 into the cabinet and the release of the gas of thereduction fluid 235 into the enclosure 210 under the conditionsdescribed above.

In some embodiments, the cabinet 230 is not required if fluid 235 isfilled directly into the enclosure 210 from an external source through avalve.

If a pump is not provided, in order to speed delivery of the gas intoenclosure 210, the cabinet 230 is disposed at a top region of theenclosure 210 when the molecular weight of the fluid 235 is larger thanthe molecular weight of the gas within the carrier 200. For example,assume that the fluid 235 is NH₃ and the gas within the carrier 200 is amixture of NH₃ and He. The molecular weight of NH₃ is 17 and themolecular weight of He is 2. If the gas comprises 10% NH₃ and 90% He,the molecular weight of the gas is about 3.5, which is less than 17.Thus, the cabinet 230 is disposed at the top region of the enclosure 210so that NH₃ efficiently diffuses into the enclosure 210 when the valve240 is actuated. In contrast, the cabinet 230 is disposed at a bottomregion of the enclosure 210 if the molecular weight of the fluid 235 isless than the molecular weight of the gas within the carrier 200. Forexample, assume that the fluid 235 comprises H₂ and the gas within thecarrier 200 comprises a mixture of H₂ and nitrogen. The molecular weightof H₂ is 2 and the molecular weight of nitrogen is 28. If the gascomprises 1% H₂ and 99% nitrogen, the molecular weight of the gas isabout 27.74, which is larger than 2. Therefore, the gas of the fluid 235within the cabinet 230 disposed at the bottom region of the enclosure210 efficiently diffuses into the enclosure 210 when the valve 240 isactuated. Note that the “top region” is not limited to the top wall 260as shown in FIG. 2A. The top region can be the top portion of thesidewall 260 of the enclosure 210. Also, the bottom region can be thebottom portion of the sidewall 260 of the enclosure 210.

The configuration of the cabinet 230 is not strictly required asdescribed above. The gas released from the fluid 235 can uniformlydiffuse within the enclosure 210 if there is sufficient time for the gasto diffuse. If the gas diffuses within the enclosure 210 in a mannerthat effectively prevents oxidation or other chemical reactions with thesubstrate 280, the cabinet 230 can be disposed at any desired location.

In some embodiments, transfer of the substrate 280 is performed withinan environment such that air will not flow into the enclosure 210 whenthe door 220 is removed. In this embodiment, the fluid 235 can be, forexample, a fluid of a non-reactive gas to the substrate 280 (e.g., aninert gas or nitrogen) without need for the reduction fluid.

Again referring to FIG. 2A, in one embodiment, the pressure gauge 261and the release valve 263 are disposed on the sidewall 260 of theenclosure 210. The pressure gauge 261 is adapted to sense the pressurewithin the carrier 200. The release valve 263 is adapted to adjust thepressure within the carrier 200 when the pressure within the carrier 200is higher than a desired pressure limit, such as about 2.5 atm.Adjusting the pressure within the carrier 200 can prevent potentialexplosions resulting from a volatile reduction gas within the carrier200 as described above. In some embodiments, the pressure gauge 261senses the pressures within and outside the carrier 200. If the pressurewithin the carrier 200 is higher than the pressure outside the carrier200 by a certain amount, the pressure gauge 261 sends a signal to thevalve 263 to trigger release of at least some of gas within the carrier200.

In some embodiments, the release valve 263 comprises a spring (notshown) which has a mechanical property such that the pressure within thecarrier 200 presses the spring to open the release valve 263. For thoseembodiments, the pressure gauge 261 is not required as the release valve263 is pressure sensitive and configured as needed. In otherembodiments, the release valve 263 comprises a piezoelectric materialwhich has a material property such that the pressure within the carrier200 presses the piezoelectric material to generate a signal to turn onthe release valve 263. For this embodiment, the pressure gauge 261 isalso not required though it can still be coupled to the valve 240.

Referring to FIG. 2A, the walls 260 of the enclosure 210 comprise one ormore than one substrate holders 270. The substrate holders 270 areprovided to support the substrates 280. The substrate holders 270 canbe, for example, plates, small extrusions on or grooves within the walls260 or other holding structures capable of holding the substrate 280.

FIG. 2B is a schematic end view of an exemplary carrier 200 shown withthe door 220 of the carrier 200 removed. In FIG. 2B like items areindicated by like reference numbers as in FIG. 2A. In this view, thesealing apparatus 215 can be seen disposed around the opening of theenclosure 210.

FIG. 3A is a schematic cross-sectional view of an exemplary facilityinterface system. The facility interface system comprises an enclosure300. The enclosure 300 comprises a sealed space 310 having a gas thereinand at least one door 325 on or in at least one of the walls 320 of theenclosure 300. The gas comprises a gas as described above in connectionwith the description of carrier 200, e.g., a reduction gas, non-reactivegas or mixture thereof. At least one robot 330 is disposed within theenclosure 300. At least one stage 340 is disposed outside of the sealedspace 310 and on or proximate to an outer surface of one of the walls320 of the enclosure 300 proximate to the door 325 for supporting theenclosure 210. Optionally, the enclosure 210 can be directly coupled toand be supported by the wall 320 of the enclosure 300. The door 325 isprovided so that the substrates 280 stored in the enclosure 210 can beproperly transferred between the enclosure 210 and the facilityinterface. At least one valve is provided for the enclosure 300. In someembodiments, the enclosure 300 includes a valve 350 and a release valve360. A pressure gauge 370 may be coupled to the valves 350 and 360. Therobot 350 operates to transfer the substrate 280 between the carrier 200and the process chamber 380 through the doors 323 and 325.

The pressure within the enclosure 300 is maintained higher than thepressure of the environment surrounding the enclosure 300 throughcooperation of the valves 350 and 360 and gauge 370 in order to preventor reduce gas flow from the environment into the enclosure 300. Forexample, if the environmental pressure is about 1 atm, the pressurewithin the enclosure 300 is maintained higher than about 1 atm.Accordingly, the pressure within the enclosure 300 can vary with theenvironmental pressure. In some embodiments, the pressure within theenclosure 300 is from about 1.0 atm to about 2.5 atm. The enclosure 300includes a gas therein including at least one of a reduction gas and anon-reactive gas with respect to the substrate 280 as described above inconnection with the enclosure 210. The reduction gas is provided toreduce or prevent oxidation on the surfaces of the substrates 280 andits levels are controlled as described above in connection with thecarrier 200.

In some embodiments, the enclosure 300 is connected to a process ortransfer chamber 380. A process chamber 380 can be, for example, a wetchemical plating bench, a dry etch chamber for via opening, a chamberfor formation of a copper seed layer, a chamber for copper chemicalmechanical polish (CMP), a chamber for formation of low-k dielectricmaterial or other chamber which forms or exposes material on thesubstrate that may react if exposed to the environment.

Referring to FIG. 3A, the valve 350 and the exhaustion valve 360 aredisposed on one of the walls 360 of the enclosure 300. The valve 350injects the mixture gas including the reduction gas into the enclosure300 from a source (not shown) to adjust the pressure therein when apressure within the enclosure 300 is lower than a predeterminedpressure, such as about 1 atm. In some embodiments, the gas introducedby the valve 350 comprises a mixture of N₂ and H₂ in which H₂ is from ofabout 4% per volume to of about 10% per volume. The exhaustion valve 360exhausts the gas from the enclosure 300 to adjust the pressure thereinwhen the pressure within the enclosure 300 is higher than anotherpredetermined pressure, such as about 2.5 atm. Rather than utilizingboth valves 350 and 360, in some embodiments, only one valve 350 or 360is used. In such embodiments, the valve 350 or 360 injects the mixturegas comprising the reduction gas into the enclosure 300 when thepressure within the enclosure 300 is lower than a predeterminedpressure, such as 1 about atm, and exhausts the mixture gas comprisingthe reduction gas from the enclosure 300 when the pressure within theenclosure 300 is higher than another predetermined pressure, such asabout 2.5 atm. In some embodiments, the valve 350 and/or the exhaustionvalve 360 is coupled to a mass flow controller (MFS) (not shown) tocontrol the flow of the gas into and out from the enclosure 310,respectively.

In some embodiments, a pressure gauge 370 is coupled to the valve 350,exhaustion valve 360 or both so that the pressure gauge 370 sends asignal to trigger the valve 350 to inject the mixture gas including thereduction gas into the enclosure 300 and the exhaustion valve 360 toexhaust the mixture gas including the reduction gas from the enclosure300 when the measured pressure reaches predetermined limits. In otherembodiments, the pressure gauge 370 is not required if the valve 350 andthe exhaustion valve 360 are time set to inject and exhaust the mixturegas comprising the reduction gas, respectively, or the valves arepressure sensitive or include integral gauges.

In some embodiments, the pressure gauge 370 senses the pressures withinand outside the enclosure 300. If the pressure within the enclosure 300is higher than the pressure outside the enclosure 300 by a predeterminedamount, the pressure gauge 370 sends a signal to trigger the exhaustionvalve 360 to release the gas within the enclosure 300 until the desiredpressure differential is reached.

In some embodiments, only the reduction gas, rather than the mixturegas, is injected into the enclosure 300 by the valve 350. However, thepressure and volume percentage of the mixture gas within the enclosureshould be maintained in such a way as described above. If the conditionsof the mixture gas within the enclosure 300 can be substantiallymaintained as described above, the injection of the reduction gas isacceptable. Factors for consideration in locating the valves 350 and 360are described above in connection with the carrier 200 and can beapplied to the enclosure 300.

FIG. 3B is an enlarged, partial view of the stage 340, enclosure 210,sealing apparatus 215 and wall 320 of the enclosure 300 shown in FIG.3A. After the door 220 of the carrier 200 is removed, the door 325 onthe wall 320 is opened so that the substrates 280 can be transferredbetween the enclosure 210 and the facility interface by the robot 330.The enclosure 210 is connected to the wall 320. The sealing apparatus215 seals the enclosure 210 against the wall 320 of the enclosure 300.In some embodiments, the pressure and gas conditions within theenclosure 300 are substantially similar to those within the carrier 200.In other embodiments, they can be different as long as such differencedoes not cause a chemical reaction on the surface of the substrate 280.

Again referring to FIG. 3A, after the substrate 280 is removed from theenclosure 210 into the enclosure 300, the door 323 between the processchamber 380 and the enclosure 300 is opened. The substrate 280 is thentransferred into the process chamber 380 for processing, and the door323 between the process chamber 380 and the enclosure 300 is closed.After the processing, the substrate 280 is transferred from the processchamber 380 into the enclosure 300. The condition within the processchamber 380 may be different from that within the enclosure 300, and theopening of the door 323 between the process chamber 380 and theenclosure 300 may destroy the desired condition within the enclosure300. However, the valve 350 and the release valve 360 are able topromptly recover the condition within the enclosure 300 back to adesired condition as described above after closing of the door 323between the process chamber 380 and the enclosure 300. The time torecover such condition may be in the order of tens of seconds, which isshort enough such that, for example, any oxidation occurring on thesurface of the substrate 280 is negligible, i.e., will not adverselyaffect the connection between the surface of the copper layer 110 and aconductive via plug filled within the via hole 130 as shown in FIG. 1.

FIGS. 4A-4C are schematic cross-sectional views illustrating anexemplary process of attaching the carrier 200 to the facility interface300 as shown in FIG. 3B.

Referring to FIG. 4A, the carrier 200 is moved approached to a wall 310a of the enclosure 310. The wall 310 a of the enclosure 310 includes thedoor 325, which is configured to cover an opening into the enclosure310. A sealing apparatus 328, such as a rubber strip, O-ring, gel orother apparatus adapted to seal the enclosure 310, is disposed on theinner surface of the wall 310 a and between the wall 310 a and the door325 so that the door 325 can be attached to the wall 310 a to tightlyseal the enclosure 310. In some embodiments, the sealing apparatus 328is disposed on the door 325 at the periphery area surrounding theopening 325 a (shown in FIG. 4C). The outer surface of the wall 310 aincludes another sealing apparatus 327, such as a rubber strip, O-ring,gel or other apparatus adapted to seal the region between the doors 220and 325 after the attachment of the carrier 200 and the wall 310 a. Thesealing apparatus 327 is adapted to seal the gap between the frame 225of the carrier 200 to the wall 310 a, when the door 220 is attached tothe wall 310 a as shown in FIG. 4B. In some embodiments, the sealingapparatus is disposed on the surface 225 a of the frame 225 surroundingthe opening 325 a (show in FIG. 4C).

At least one fasteners 322, such as clamps, knob clamps, clips or otherdevices that can fasten the carrier 200 to the wall 310 a, areconfigured on the outer surface of the wall 310 a proximate to edges ofthe sealing apparatus 327 to fasten the carrier 200, such as the frame225. The fasteners 322 can be, for example, rotated or vertically movedto fasten the carrier 200. The number of the fasteners 322 is notlimited to the number shown in FIG. 4A. It can be one or more than onefasteners 322 as long as the carrier 200 can be fastened to the wall 310a.

At least one valves, such as a valve 324 and a valve 326, configuredwithin the wall 310 a. The opening of the valves 324 and 326 areconfigured within an area enclosed by the sealing apparatus 327 toremove air from a region sealed by the sealing apparatus 327 as shown inFIG. 4B and inject an inert gas or a mixture including the reduction gasas set forth above into the region, respectively. In some embodiments,only one of the valves 324 and 326 is used if the selected valve isconfigured to allow both the removal of the air from the region sealedby the sealing apparatus 327 and the injection of an inert gas or amixture gas including the reduction gas into the region. In someembodiments, the valves 324 and/or 326 are coupled to at least one massflow controllers (MFC) to control the removal rate of air and theinjection rate of the inert gas or the mixture gas.

Referring to FIG. 4B, the carrier 200 is attached to the wall 310 a,such as the sealing apparatus 327. Under this embodiment, the surface225 a of the frame 225 is attached against the sealing apparatus 327 sothat the sealing apparatus tightly seals the gap between the doors 215and 325. The valve 324 then removes air trapped within the region sealedby the sealing apparatus 327. The valve 326 then injects the inert gasor the mixture gas within this region so that this region is filled withthe gas so that does not substantially react with the substrates 280stored in the carrier 200. In some embodiments, the cycle of the removalof the air and the injection of the inert gas or mixture gas isperformed at least one times, such as about 3-5 times, so that the airtrapped within this region sealed by the sealing apparatus 327 issubstantially removed.

Referring to FIG. 4C, the doors 325 and 220 are sequentially removed tolocations that will not interfere the transfer of the substrates 280.The locations can be, for example, proximate to the inner surface of thewall 310 a and below the opening 325 a that is covered by the door 325.In addition, the dimension of the door 220 is smaller than that of thedoor 325. The door 220 thus can be removed towards the enclosure 310after the removal of the door 325. As described above, the enclosure 310and the carrier 200 contain the gas including the reduction gas.Further, the air trapped within the region sealed by the sealingapparatus 327 and the inert gas or mixture gas is then injected intothis region. Accordingly, the substrates 280 can be transferred betweenthe enclosure 310 and the carrier 200 without substantial exposure toair. The present invention, however, is not limited thereto. Thetransfer of the substrates 280 can still be performed as set forth inconnection with FIG. 3A, for example.

FIGS. 5A-5B are plots showing a pressure change within the enclosure 210during an unloading/transfer/reloading cycle of the carrier 200 from thestage 340.

Referring to FIG. 5A, Pe represents the pressure of the environmentsurrounding the enclosure 210, P0 represents a low-level pressure, P1represents the selected pressure within the enclosure 300 of thefacility interface, P2 represents the minimum desired pressure withinthe enclosure 200 and P3 represents the maximum desired pressure withinthe enclosure 210. In some embodiments, if either the pressure of theenclosure 310 or the carrier 200 is lower than P0, it is assumed thatleakage of the gas occurs between the environment and the enclosure 310and/or the carrier 200. The enclosure 310 and/or the carrier 200 thuscan be checked before the use of transferring and carrying thesubstrates 280.

Prior to T1, the enclosure 210 is seated on the stage 340 and physicallycoupled to the enclosure 300 with the door 220 opened or removed andwith the door 325 opened as shown in FIG. 3B. Because the spaces withinthe enclosures 210 and 300 are connected, the pressure within theenclosure 210 is substantially equal to the pressure within theenclosure 300, e.g., P1. After one or more substrates 280 aretransferred to the carrier 200, at the time T1, the door 220 is attachedto or closed over the carrier 200 to seal the enclosure 210 as shown inFIG. 2A. The carrier 200 is lifted from the stage 340 and transported toa selected processing apparatus during time between times T1 to time T2.In this embodiment, the desired minimum pressure P2 within the enclosure210 is higher than the environment pressure Pe and the pressure P1maintained within the enclosure 300. In order to increase the pressurewithin the enclosure 210 to the desired minimum pressure P2, the valve240 shown in FIG. 2A operates to release the gas of the fluid 235 storedwithin the cabinet 230 into the enclosure 210 to increase the pressure.At the time T2, in order to perform a subsequent process, the enclosure210 is reloaded, i.e., seated, on a stage 340 of a facility interfaceassociated with a second process apparatus and the door 220 is removed.The enclosure 210 is physically coupled to an enclosure 300 as shown inFIG. 3B. FIG. 5A shows that the time between T1 and T2 was not longenough to allow the pressure within the enclosure 210 to reach thedesired minimum pressure P2. At time T2, because the spaces within theenclosures 210 and 300 are connected and the space within the enclosure300 is substantially larger than that within the enclosure 210, thepressure within the enclosure 210 is pulled down and maintainedsubstantially equal to the pressure P1 within the enclosure 300.

The timeline of FIG. 5B shows the operation of the carrier 200 whensufficient time passes from a time T1 (where the carrier 200 is unloadedfrom a facility interface) for the pressure within the carrier 200 toreach the desired minimum pressure P2. From time T1 to time T4,substrates 280 are stored and/or transported within the carrier 200. Attime T3, the pressure reaches the desired minimum pressure P2, and fromtime T3 to T4 the pressure is maintained within the desired pressurerange (P2 to P3) by operation of valves 240, 250, 263, pressure gauge261 and/or cabinet 230. At time T4, the carrier 200 is again loaded ontoa stage of a facility interface. The door 220 of the carrier 200 isopened or removed and the carrier 200 is coupled to an enclosure 300, atwhich time the pressure equalizes with the pressure P1 of the enclosure300.

In still other embodiments, after the door 220 is closed, the valve 240injects the reduction gas into the carrier 200. The release valve 263,such as a spring, releases the gas within the carrier 200 to theenvironment if the pressure within the carrier 200 is higher than P2without the use of the pressure gauge 261.

Although FIGS. 5A-5B illustrate the operation of embodiments where P1 isless than P2, in some embodiments, the desired pressure to be maintainedwithin the enclosure 210 is substantially equal to the pressure withinthe enclosure 310. In still other embodiments, the desired pressure tobe maintained within the enclosure 210 is lower than the pressure withinthe enclosure 310 but above the environment pressure Pe.

Although the present invention has been described in terms of exemplaryembodiments, it is not limited thereto. Rather, the appended claimsshould be constructed broadly to include other variants and embodimentsof the invention which may be made by those skilled in the field of thisart without departing from the scope and range of equivalents of theinvention.

1. A carrier, comprising: an enclosure comprising a plurality of wallsand a door; a cabinet coupled to the carrier within the enclosure, thecabinet comprising a valve and containing a fluid; wherein the valve isoperable to introduce said fluid into said enclosure, and the fluid isselected from the group consisting of a reduction fluid and anon-reactive fluid; and a substrate holder disposed within the enclosureto support a substrate.
 2. The carrier of claim 1, wherein the pressurewithin the carrier is maintained at a pressure higher than the pressureof the environment surrounding the carrier.
 3. The carrier of claim 2,further comprising means for maintaining the pressure within the carrierwithin a selected pressure range.
 4. The carrier of claim 3, wherein theselected pressure range is from about 1.0 atm to about 2.5 atm.
 5. Thecarrier of claim 1, further comprising a sealing apparatus disposedbetween the enclosure and the door to seal the carrier when the door isin a closed position, and to seal the enclosure and an interfaceapparatus when the door is in an open position or removed.
 6. Thecarrier of claim 1, wherein the cabinet comprises a first valve and asecond valve, the second valve positioned to allow release of a gas ofthe fluid into the enclosure when a pressure within the enclosure islower than a predetermined pressure level, and the first valve ispositioned to allow filling of the fluid into the cabinet.
 7. Thecarrier of claim 6, wherein the predetermined pressure level is about 1atm.
 8. The carrier of claim 1, wherein the reduction fluid comprises amixture of hydrogen (H₂) and ammonia (NH₃), and the mixture is in gas orliquid form.
 9. The carrier of claim 8, wherein the cabinet is disposedproximate to a bottom region of the enclosure and a molecular weight ofthe reduction fluid is less than a molecular weight of a gas within thecarrier, or the cabinet is disposed at a top region of the enclosure andthe molecular weight of the reduction fluid is more than the molecularweight of the gas within the carrier.
 10. The carrier of claim 1 furthercomprising a gas within the enclosure, wherein the gas comprises areduction gas or a non-reactive gas with respect to a surface of thesubstrate.
 11. The carrier of claim 10, wherein the reduction gascomprises at least one of hydrogen and ammonia, and the non-reactive gascomprises at least one of an inert gas and nitrogen.
 12. The carrier ofclaim 11, wherein hydrogen is equal to or less than about 4% per volumeand ammonia is equal to or less than about 15.5% per volume.
 13. Thecarrier of claim 1 further comprising a release valve within theenclosure, the release valve being actuated to adjust a pressure withinthe carrier if the pressure is higher than a predetermined pressurelevel.
 14. The carrier of claim 13, wherein the predetermined pressurelevel is about 2.5 atm.
 15. The carrier of claim 13 further comprising apressure gauge coupled to the release valve.